Improved performance of organosilica membranes for steam recovery at moderate-to-high temperatures via the use of a hydrothermally stable intermediate layer
Improved performance of organosilica membranes for steam recovery at moderate-to-high temperatures via the use of a hydrothermally stable intermediate layer
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DOI：
10.1016/j.memsci.2020.118895
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发表时间：
2020-11
影响因子：
9.5
通讯作者：
Norihiro Moriyama;Hiroki Nagasawa;M. Kanezashi;T. Tsuru
中科院分区：
文献类型：
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作者：
Norihiro Moriyama;Hiroki Nagasawa;M. Kanezashi;T. Tsuru
为了研究有机硅膜在水热条件下蒸汽回收的未来应用前景，我们提出了一个新的概念，其中涉及源自胶体1,2-双（三乙氧基甲硅烷基）乙烷（BTESE）溶胶的水热稳定中间层和源自BTESE的分离顶层。本工作利用无针孔或裂纹的BTESE衍生胶体溶胶制备了BTESE衍生纳米多孔中间层（i-BTESE），然后在i-BTESE上形成BTESE衍生亚纳米孔分离层，得到BTESE/i-BTESE膜。 BTESE/i-BTESE膜表现出高达5×10-6mol/(m2sPa)的优异透水性，并且在200°C、200kPa(绝对)蒸气压下保持高水平的渗透性长达361小时。此外，即使在 361 小时后，该膜的 H2O/N2 渗透率仍高达 350。另一方面，使用二氧化硅-氧化锆中间层的传统BTESE膜（BTESE/i-SiO2-ZrO2）的渗透性逐渐下降，这表明BTESE/i-SiO2-ZrO2膜发生了降解。 BTESE/i-BTESE 膜的高性能和稳定性证实了所提出的概念，即水热稳定的中间层可以显着提高在蒸汽回收中使用有机硅膜所需的水热稳定性。
To examine the prospect of a future application of organosilica membranes to steam recovery under hydrothermal conditions, we proposed a novel concept that involved a hydrothermally stable intermediate layer derived from colloidal 1,2-bis(triethoxysilyl)ethane (BTESE) sols with a BTESE-derived separation top layer. In this work, a BTESE-derived nanoporous intermediate layer (i-BTESE) was prepared from a BTESE-derived colloidal sol without pinholes or cracks, and then a BTESE-derived sub-nanoporous separation layer was formed on the i-BTESE to obtain a BTESE/i-BTESE membrane. The BTESE/i-BTESE membrane showed excellent water permeance as high as 5 × 10-6mol/(m2s Pa), and a high level of permeance was maintained for as long as 361 h at 200°C under vapor pressure of 200 kPa (abs.). In addition, the membrane achieved an H2O/N2permeance ratio that reached as high as 350 even after 361 h. On the other hand, the permeance of a conventional BTESE-derived membrane that used a silica-zirconia intermediate layer (BTESE/i-SiO2-ZrO2) decreased gradually, which suggested a degradation of the BTESE/i-SiO2-ZrO2membrane. The high and stable performance of the BTESE/i-BTESE membrane confirmed the proposed concept whereby a hydrothermally stable intermediate layer could significantly improve the hydrothermal stability that is required in order to use organosilica membranes in steam recovery.